Dynamic changes in nocturnal blood glucose levels are associated with sleep-related features in patients with obstructive sleep apnea

Mulberry leaf extract combined with tryptophan improves sleep and post wake mood in adults with sleep complaints - A randomized cross-over study

PURPOSE

In the current study we evaluated a blend of ingredients containing mulberry leaf extract (to lower postprandial glucose of the evening meal), tryptophan (facilitator of the sleep initiation) to benefit sleep initiation and quality in adults with self-reported difficulties with sleep initiation.

METHODS

Forty-three adults aged between 25 and 50 years enrolled in a randomized, crossover, double-blind, controlled trial. Participants received standardized meals with a glycemic load of 55 ± 10% and were assigned to receive treatment comprising a combination of mulberry leaf extract (750 mg), whey protein containing 120 mg tryptophan, zinc (1.35 mg), magnesium (12.6 mg), vitamin B3 (1.93 mg) and B6 (0.135 mg) and control (4 g wheat protein hydrolysate). Each intervention phase lasted 14 days separated by a washout period of 28 days. The primary outcomes were actigraphy-measured sleep onset latency and sleep efficiency. Secondary outcomes included continuous glycemic responses, mood, and cognition.

RESULTS

A linear mixed model intention-to-treat analysis conducted on 42 participants found that the treatment reduced sleep onset latency (actigraphy: -3.82 mins, p = 0.026; self-report: -3.09 mins, p = 0.048). Treatment significantly reduced evening meal's postprandial glucose response (incremental area under the curve, mmol/L*min) at 1 hour by 21% (p < 0.001), incremental maximum concentration by 16% (p = < 0.001) and nocturnal glucose variation over the 14-day period. Participants on treatment reported improved sleep quality (Karolinska Sleepiness Scale, -0.17, p = 0.041) and feeling more relaxed (Brief Mood Introspection Scale, -0.4, p = 0.003) the next morning compared to when taking the control. Additionally, the treatment improved the vigor dimension on the Profile of Mood Scale (0.8, p = 0.038). No effects were observed on the cognitive performance. Lowering postprandial glucose significantly mediated the treatment effect of lowering sleep onset latency and lower nocturnal glucose variation was also associated with improved sleep quality and next-day positive mood.

CONCLUSION

The evening meal supplement benefited sleep initiation and quality, and also improved post wake mood in adults.

TRIAL REGISTRATION

Registration number of Clinical Trial - ClinicalTrials.gov NCT05372900.

Association of Obstructive Sleep Apnea and Nocturnal Hypoxemia With the Circadian Rhythm of Myocardial Infarction

BACKGROUND

The circadian rhythm of myocardial infarction (MI) in patients with obstructive sleep apnea (OSA) remains disputable and no studies have directly evaluated the relationship between nocturnal hypoxemia and the circadian rhythm of MI. The aim of the current study was to evaluate the association of OSA and nocturnal hypoxemia with MI onset during the night.

METHODS

Patients with MI in the OSA-acute coronary syndrome (ACS) project (NCT03362385) were recruited. The time of MI onset was identified by patient's report of the chest pain that prompted hospital admission. All patients underwent an overnight sleep study using a type III portable sleep monitoring device after clinical stabilization during hospitalization. The difference in circadian variation of MI onset was evaluated between patients with moderate/severe OSA and non/mild OSA and those with or without nocturnal hypoxemia. Nocturnal hypoxemia was evaluated using 3 variables, including oxygen desaturation index, minimum oxygen saturation, and total sleep time with saturation <90%.

RESULTS

Among 713 patients enrolled, 398 (55.8%) had moderate/severe OSA (apnea-hypopnea index ≥15 events·h - 1). Compared with the non/mild OSA group, the MI onset was significantly increased in the moderate/severe OSA group between midnight to 5:59 am in 6-hour epochs analysis (26.9% versus 18.4%, P=0.008). Only in patients with both moderate/severe OSA and nocturnal hypoxemia, including oxygen desaturation index ≥15, minimum oxygen saturation ≤86%, and total sleep time with saturation <90% ≥2%, the incidence of MI onset between midnight to 5:59 am was significantly increased. Moderate/severe OSA (adjusted odds ratio 1.66 [95% CI, 1.13-2.43]; P=0.01) and nocturnal hypoxemia (oxygen desaturation index ≥15 model, adjusted odds ratio 1.80, [95% CI, 1.21-2.66]; minimum oxygen saturation ≤86% model, adjusted odds ratio 1.70 [95% CI, 1.16-2.47]; P=0.006; total sleep time with saturation <90% ≥2% model, adjusted odds ratio 1.54 [95% CI, 1.04-2.27]; P=0.03) significantly predicted MI occurrence from midnight to 6:00 am.

CONCLUSIONS

A peak of incident MI onset between midnight to 5:59 am was observed in patients with moderate/severe OSA, especially in those presenting with nocturnal hypoxemia.

Non-Invasive Continuous Glucose Monitoring in Patients Without Diabetes: Use in Cardiovascular Prevention-A Systematic Review

Continuous glucose monitoring (CGM) might provide immediate feedback regarding lifestyle choices such as diet and physical activity (PA). The impact of dietary habits and physical activity can be demonstrated in real time by providing continuous data on glucose levels and enhancing patient engagement and adherence to lifestyle modifications. Originally developed for diabetic patients, its use has recently been extended to a non-diabetic population to improve cardiovascular health. However, since data in this population are scarce, the effect on cardiovascular outcomes is unclear. CGM may offer potential benefits for cardiovascular prevention in healthy individuals without diabetes. The aim of this systematic review is to evaluate the use of CGM in healthy non-diabetic individuals, focusing on its potential to guide lifestyle interventions in the context of cardiovascular prevention, which may ultimately reduce cardiovascular risk.

Implications of sleep disorders for periodontitis

PURPOSE

Periodontitis is a chronic inflammatory disease caused by multi-factors. Sleep is a natural physiologic process, and the sleep duration, quality, and patterns might be associated with periodontitis. Meanwhile, periodontitis might in turn induce systemic inflammation and thus impact sleep in different ways as well.

METHODS

To investigate the bidirectional relationship between sleep disorder and periodontitis, a literature search was conducted to reveal the interaction and possible mechanism between these two diseases.

RESULTS

The results show that sleep disorders can affect the progression of periodontitis via some pathomechanisms, and periodontitis also has a reverse impact on sleep.

CONCLUSION

Although the epidemiologic and clinical trials found the possible associations between sleep disorder and periodontitis, their relationship is still not that explicit. Further studies are warranted to shed light on them, to improve preventive health care.

Sleep Apnea and Cardiovascular Risk in Patients with Prediabetes and Type 2 Diabetes

Obstructive sleep apnea (OSA) is a common but largely undiagnosed clinical condition, which is turning into a serious public health issue. Of note is that its prevalence is gradually increasing in parallel with the obesity and type 2 diabetes mellitus (T2DM) epidemics. The aim of this article is to comprehensively review the literature in order to evaluate the cardiovascular (CV) risk among patients with OSA and prediabetes or T2DM. OSA seems to be an independent risk factor for the development as well as the progression of T2DM, whereas it is associated with T2DM-related macrovascular and microvascular complications. OSA may also act as a potential risk factor for the presentation and development of CV disease, such as hypertension, coronary artery disease, heart failure, pulmonary hypertension, atrial fibrillation and other cardiac arrythmias, as well as stroke. OSA and T2DM also share common pathophysiological mechanisms leading to atherosclerosis. Considering that the coexistence of OSA and T2DM is an independent and cumulative risk factor for CV mortality, more so than the two diseases separately, clinicians and healthcare professionals should be aware of and screen for OSA in patients with T2DM. Notably, targeted therapy for both conditions seems to substantially improve CV prognosis.

Obstructive sleep apnea, prediabetes and progression of type 2 diabetes: A systematic review and meta-analysis

AIMS/INTRODUCTION

Obstructive sleep apnea (OSA) is related to prediabetes and diabetes. Whether patients with OSA have a higher risk of prediabetes/diabetes remains unclear. We aimed to carry out a meta-analysis of published studies to evaluate the relationships between OSA and prediabetes and diabetes, and the impact of the severity of OSA on diabetes.

MATERIALS AND METHODS

The PubMed, EMBASE and Cochrane databases were searched from January 2011 to July 2021. The associations between OSA and impaired fasting glucose, impaired glucose tolerance, impaired glucose regulation and diabetes mellitus were analyzed. We estimated the pooled odds ratios using fixed or random effects models. We included 25 studies comprising a total of 154,948 patients with OSA and risk factors for prediabetes/diabetes (20 and 16, respectively) in the analysis.

RESULTS

OSA was associated with a higher risk of impaired fasting glucose, impaired glucose tolerance, impaired glucose regulation and diabetes mellitus in the cohort studies and cross-sectional studies. The pooled odds ratios were 2.34 (95% confidence interval [CI] 1.16-4.72), 1.58 (95% CI 1.15-2.15), 1.65 (95% CI 1.12-2.42), 2.15 (95% CI 1.68-2.75) and 3.62 (95% CI 2.75-4.75), respectively. Subgroup analyses were based on the proportions of men and women. The results showed that OSA was a risk factor, and there was no significant difference between the two groups. The risk of diabetes increased with the severity of OSA.

CONCLUSIONS

The risk of developing prediabetes and diabetes was higher in patients with OSA.

Postprandial glucose and HbA1c are associated with severity of obstructive sleep apnoea in non-diabetic obese subjects

INTRODUCTION

Obstructive sleep apnoea (OSA) is an underdiagnosed condition frequently associated with glycaemic control impairment in patients with type 2 diabetes.

AIM

To assess the relationship between glycometabolic parameters and OSA in obese non-diabetic subjects.

METHODS

Ninety consecutive subjects (mean age 44.9 ± 12 years, mean BMI 42.1 ± 9 kg/m²) underwent polysomnography and a 2-h oral glucose tolerance test (OGTT).

RESULTS

OSA was identified in 75% of subjects, with a higher prevalence of males compared to the group of subjects without OSA (62% vs 32%, p = 0.02). Patients with OSA had comparable BMI (42.8 kg/m² vs 39.4 kg/m²), a higher average HbA1c (5.8% vs 5.4%, p < 0.001), plasma glucose at 120 min during OGTT (2 h-PG; 123 mg/dl vs 97 mg/dl, p = 0.009) and diastolic blood pressure (81.1 mmHg vs 76.2 mmHg, p = 0.046) than obese subjects without OSA. HbA1c and 2 h-PG were found to be correlated with the apnoea-hypopnoea index (AHI; r = 0.35 and r = 0.42, respectively) and with percent of sleep time with oxyhaemoglobin saturation < 90% (ST90; r = 0.44 and r = 0.39, respectively). Further, in a linear regression model, ST90 and AHI were found to be the main determinants of 2 h-PG (β = 0.81, p < 0.01 and β = 0.75, p = 0.02, respectively) after controlling for age, sex, waist circumference, physical activity, and C-reactive protein. Similarly, ST90 and AHI persisted as independent determinants of HbA1c (β = 0.01, p = 0.01 and β = 0.01, p = 0.01, respectively).

CONCLUSION

Beyond the traditional clinical parameters, the presence of a normal-high value of 2 h-PG and HbA1c should raise suspicion of the presence of OSA in obese subjects.

Sleep quality and glycaemic variability in a real-life setting in adults with type 1 diabetes

AIMS/HYPOTHESIS

Suboptimal subjective sleep quality is very common in adults with type 1 diabetes. Reducing glycaemic variability is a key objective in this population. To date, no prior studies have examined the associations between objectively measured sleep quality and overnight glycaemic variability in adults with type 1 diabetes. We aimed to test the hypothesis that poor sleep quality would be associated with greater overnight glycaemic variability.

METHODS

Data were collected in the home setting from 20 adults (ten male and ten female participants) with type 1 diabetes who were current insulin pump users. Simultaneous assessments of objective sleep quality (Zmachine Insight+) and continuous glucose monitoring (CGM) were performed over multiple nights (up to 15 nights) in each participant. Due to the real-life nature of this study, the participants kept their usual CGM alerts for out-of-range glucose values. Sleep quality was categorised as 'good' or 'poor' using a composite of objective sleep features (i.e. sleep efficiency, wake after sleep onset and number of awakenings) based on the National Sleep Foundation's consensus criteria. Glycaemic variability was quantified using SD and CV of overnight glucose values based on overnight CGM profiles.

RESULTS

A total of 170 nights were analysed. Overall, 86 (51%) nights were categorised as good sleep quality, and 84 (49%) nights were categorised as poor sleep quality. Using linear mixed-effects models, poor sleep quality was significantly associated with greater glycaemic variability as quantified by SD (coefficient: 0.39 [95% CI 0.10, 0.67], p = 0.009) and CV (coefficient: 4.35 [95% CI 0.8, 7.9], p = 0.02) of overnight glucose values, after accounting for age, sex, BMI and overnight insulin dose. There was large inter- and intra-individual variability in sleep and glycaemic characteristics. Both pooled and individual-level data revealed that the nights with poor sleep quality had larger SDs and CVs, and, conversely, the nights with good sleep quality had smaller SDs and CVs. No associations were found between sleep quality and time spent in the target glucose range, or above or below the target glucose range, where CGM alarms are most likely to occur.

CONCLUSIONS/INTERPRETATION

Objectively measured sleep quality is associated with overnight glycaemic variability in adults with type 1 diabetes. These findings highlight an important role of sleep quality in overnight glycaemic control in type 1 diabetes. They also provide a strong incentive to both patients and healthcare providers for considering sleep quality in personalised type 1 diabetes glycaemic management plans. Future studies should investigate the mechanisms linking sleep quality to glycaemic variability.

Impact of obstructive sleep apnea complicated with type 2 diabetes on long-term cardiovascular risks and all-cause mortality in elderly patients

BACKGROUND

The prognostic significance of obstructive sleep apnea (OSA) in elderly patients with type 2 diabetes is unclear. The aim of this study was to determine the risk of cardiovascular disease (CVD) and mortality in elderly patients with OSA complicated with type 2 diabetes compared to patients with OSA without type 2 diabetes.

METHODS

From January 2015 to October 2017, 1113 eligible elderly patients with OSA, no history of cardiovascular, ≥60 years of age, and complete follow-up records were enrolled in this consecutive multicentre prospective cohort study. All patients had completed polysomnography (PSG) examinations. An apnoea-hypopnoea index of ≥5 events per hour recorded by polysomnography was defined as the diagnostic criterion for OSA. We collected baseline demographics, clinical characteristics, sleep parameters and follow-up outcomes. The primary aim of this study was to identify the risk of incident major adverse cardiovascular events (MACE). Secondary outcomes were all-cause mortality, components of MACE and a composite of all events. Kaplan-Meier survival analysis and Cox proportional hazards models were used to evaluate whether type 2 diabetes was associated with incident events.

RESULTS

A total of 266 (23.9%) patients had OSA complicated with type 2 diabetes. MACE occurred in 97 patients during the median 42-month follow-up. Kaplan-Meier survival curves indicated a significant relationship between type 2 diabetes and MACE (log-rank P = 0.003). Multivariable Cox regression analysis showed that type 2 diabetes increased the risk of MACE (HR = 1.64, 95% CI:1.08-2.47, P = 0.019), hospitalisation for unstable angina (HR = 2.11, 95% CI:1.23-3.64, P = 0.007) and a composite of all events in elderly patients with OSA (HR = 1.70, 95% CI:1.17-2.49, P = 0.007). However, there were no significant differences in the incidence of cardiovascular death, all-cause mortality, MI and hospitalisation for heart failure between patients with and without diabetes (P > 0.05). The subgroup analysis demonstrated that females (AHR = 2.46, 95% CI:1.17-5.19, P = 0.018), ≥ 70 years (AHR = 1.95, 95% CI:1.08-3.52, P = 0.027), overweight and obese (AHR = 2.04, 95% CI:1.29-3.33, P = 0.002) with mild OSA (AHR = 2.42, 95% CI: 1.03-5.71, P = 0.044) were at a higher risk for MACE by diabetes.

CONCLUSION

OSA and type 2 diabetes are interrelated and synergistic with MACE, hospitalisation for unstable angina and a composite of all events development. Overweight and obese females, ≥ 70 years with mild OSA combined with type 2 diabetes presented a significantly high MACE risk.